[rantallion]

> and the software would translate ... in real-time

Depending on the pair of languages being translated between, isn't this literally impossible? The ordering of sentence parts is not the same in all languages (coincidentally, Japanese and English are a perfect example here of how different grammar can be), so you often have to wait until you've heard the whole sentence before you can parse it translate into another language.

Given the above issue, how is what you're envisioning any better than just using Google Translate?

[LargeTomato]

In Arabic there is no word for "uncle". There is only "dad's brother" and "mom's brother". Often times an English speaker will leave out the paternal/maternal portion and the Arabic sentence may be ambiguous. If the English speaker later specified the needed information and the Arabic translator guessed wrong then there's a confusing problem here and the Arabic listener might get confused.

[karmakaze]

Is there no structure to express a parent's (or father's or mother's) brother? It may not flow well but avoids making incorrect assumptions.

[rootsu]

In my language, there are two different words for Maternal uncle and Paternal uncle, so translating from English without any context might completely change the relationship.

[nrmitchi]

This is the kind of failure of expectations that Star Trek’s universal translator has set us up for.

As far as I know you’re right, a number of things either don’t translate, or are too contextual for real time translation.

I’d love to be proven wrong, but I think the underlying problem here isn’t necessarily the language itself, but differences in underlying mental models that the languages express.